1. Field of the Invention
The present invention relates generally to a heat staking apparatus for joining two or more workpieces and, more particularly, to a compact, self-controlled staking apparatus for joining two or more workpieces.
2. Description of the Related Art
Heat staking is a well-known process for permanently joining two or more of parts at one or more discrete locations. In the heat staking process, one of the joined parts includes a short thermoplastic post or stud that is inserted through a hole or aperture in the mating part. The stud is heated until it is plastically deformable and then shaped or otherwise deformed by a suitable staking tool to form a rivet-like end on the stud that secures the mating parts together.
Known heat staking machines, such as the machine disclosed in U.S. Pat. No. 6,093,277, are configured to repetitively assemble a single article or a family of articles. Known heat staking machines are relatively large and typically employ one or more staking tools assembled on a support structure and a separate control system to facilitate heating of the staking tool prior to deforming the stud. To reconfigure or “retool” these machines, each individual staking tool must be disassembled from the control system and rearranged or removed from the heat staking machine. Additionally, known staking machines typically employ a single control system for several heat staking tools, which idles all the staking tools when the control system is rendered inoperable. Accordingly, there exists a need for a compact, self-controlled staking apparatus that can be readily configurable, either alone or in combination with several similar staking apparatus, to assemble a single article or a family of articles.